protein expression unclassified drug nonhuman 375 controlled study 342 priority journal 325 article 304 Animals 277 human 231 Humans 214 animal cell 193 protein function 154 mouse 140 animal experiment 139 metabolism 138 Mice 129 human cell 127 Article 116 animal 110 Female 99 signal transduction 96 female 95 animal tissue 89 enzyme activity 87 messenger RNA 85 animal model 76 male 76 gene expression 70 genetics 69 Male 68 cell proliferation 64